Judging from the photos I have seen, from lightwerkz and ChasWG's write up, it looks like there is plenty of wire for the ballast to sit outside the housing. It would be nice if ChasWG could chime in as to if he had to drill or if there was enough cable to place the ballast outside the housing...

I know Chas, and he did have to drill through the dust caps. As you need to do with any xenon retro fit kit. It really is no big deal.

and both the ballast and ignitor are outside of the housing, that is why you need to drill, power from the original plug to the ballast, those wires go out of the housing to the ballast, then the wires to power the ignitor, and wires from the ignitor to the bulb, those wires go back through the dust cover. All 4 wires are encased in a grommet that fills the hole you drill.